Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 232 PM EDT Sun Apr 05 2015 Valid 00Z Mon Apr 06 2015 - 00Z Wed Apr 08 2015 ...Welcome precipitation expected near the West coast into Tuesday... ...An expanding area of thunderstorms moves across the Gulf Coast and East... ...The specter of flash flooding returns to portions of Kentucky and the upper Ohio Valley Monday night into Tuesday... The main player weatherwise this period is a burgeoning upper level disturbance strengthening as it expands into the West coast. Its associated cool pool of air aloft is expected to destabilize the atmosphere, and when combined with onshore flow from the eastern Pacific ocean, should lead to moderate to heavy welcome rains near portions of the West coast for the next couple days with interior and higher elevation snows falling across the Northwest and Sierra Nevada. Ahead of this system, a low pressure system organizes over Wyoming before dropping down into the central Plains by Tuesday morning and moving into the Midwest later Tuesday. Pacific moisture advects in aloft while Gulf of Mexico moisture invades closer to the surface, leading to an expanding and northeast moving area of showers and thunderstorms urged by the cyclone's associated warm front, with embedded heavy rainfall, moving from the western Gulf coast through the Southeast and Ohio Valley over the next couple of days. The rains near the upper Ohio Valley are not needed, as soils are saturated from the recent flooding/flash flooding from this past Wednesday night and Thursday. Across the northern Plains and interior New England, weak disturbances aloft associated with the northern belt of the Westerlies should lead to skirmishes with frozen precipitation, mostly in the form of snow. The exception appears to be central Wisconsin, where freezing rain and sleet are possible Tuesday morning as warm air invades aloft over the chilly air near the surface. Roth Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php